The objective of this task is to develop and test superior gas separation membranes. Several methods will be tested to prepare new membrane materials, including physical vapor deposition via electron beam evaporation. Other ceramic filter materials used in hot-gas particulate filters will be obtained from selected suppliers for use as substrates to develop a thin-film membrane selective to hydrogen permeation. This thin-film membrane will be modified via an EERC proprietary process. The base filter materials will already have been characterized for hydrothermal and chemical stability and pore size. The selectivity of these membrane materials for separating undesired gases will be determined. Selectivity will be measured by mixing bottled gases in a manifold, feeding the gases to the membrane, and sampling the inlet, permeate, and raffinate streams for gas composition and volumetric flow rate. Specific questions to be answered include the following: What are the effects of ceramic membrane properties (i.e., surface area, pore size, and coating thickness) on permeability and selectivity of the desired gases? What are the effects of operating conditions (i.e., temperature, pressure, and flow rate) on permeability and selectivity?